


Down to the Root

by Myqueenmarceline



Category: Adventure Time, Person of Interest (TV)
Genre: Alternate Universe - Spies & Secret Agents, Crossover, F/F, Not super graphic yet but that may change, some violence mentioned
Language: English
Status: In-Progress
Published: 2020-08-05
Updated: 2020-09-03
Packaged: 2021-03-05 22:34:24
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 1,848
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25732921
Author URL: https://archiveofourown.org/users/Myqueenmarceline/pseuds/Myqueenmarceline
Summary: An adventure time/person of interest crossover I wrote entirely for myself, where Marceline takes the place of Agent Shaw and Bonnibel takes the place of Root.
Relationships: Princess Bubblegum/Marceline
Comments: 11
Kudos: 28





	1. Your Call

**Author's Note:**

> For those of you who haven't seen person of interest, here is what you need to know:  
> There is an all-seeing machine that prevents violent crimes by predicting events before they happen called The Machine. Shaw and Root (Marceline and PB) are both working to help the machine.  
> -Marceline is an ex-government agent who was betrayed and is now fighting for the machine  
> -PB is a hacker and former contract killer who is the only one in direct contact with the machine, and has a special relationship with it  
> -Schwabl is an attack dog who responds to commands in dutch and was rescued from white supremacists
> 
> I just wanted to explore this AU a little bit, let me know if y'all enjoy it!
> 
> (I will add other characters/descriptions as needed)
> 
> Also: thank you to nebula-gaster for beta reading this, I appreciate it!

Marceline was in the middle of patching herself up when the call came in. She let her phone ring, carefully extracting the remnants of the hollow point’s shell from her hip. The pain made her head spin, and she gritted her teeth as she hissed softly. She would still have to clean her wound out, but that might happen after she passed out once from the pain.

For one blissful moment, the phone stopped ringing. The only sounds in the room were Marceline’s pained breathing and Schawbl whimpering nearby. Marceline closed her eyes, letting her head rest against the back of the wooden chair she was sitting in. It wasn’t the most comfortable way to pass out, but Marceline had been through worse before.

Then, the phone began ringing again.

Marceline groaned, and fought the urge to bang her head against the chair until she knocked herself out. There was only one person who would try to call her twice in a row, and she would keep calling until she got an answer. Marceline was tired, but she didn’t want to give Bonnibel a heart attack.

She picked up the phone, glaring down at it as if it had kicked Schwabl. The number was blocked, but that didn’t mean anything. She answered the call and hit speakerphone, then reached for the bottle of rubbing alcohol.

“Hey sweetie, you busy?” Bonnibel’s voice was slightly staticky through the phone, but Marceline would recognize that tone of voice anywhere. It was sugary sweet, but it promised only pain.

“What do you want?” Marceline mumbled in reply, frowning as Schwabl’s tail began to wag. Traitor.

“Want to come on a mission with me? I promise we can go someplace warm afterwards. A nice little island off the map.” Bonnibel sounded amused, which meant this was going to be difficult. She acted like these missions were just games, and it was annoying as hell sometimes.

If her presence was really necessary, Bonnibel wouldn’t be asking her to come along. She would just tell Marceline when and where to be. She must actually want to spend time with Marceline. Marceline could try and put up a cold front, but she had missed Bonnibel these past few weeks. She was always so upbeat, and very nice to look at. Their mission might be difficult, but Marceline knew that Bonnibel would have her back.

“Fine.” Marceline briefly thought of Bonnibel in a swimsuit, then poured half the bottle on to her wound to distract herself. She hissed, biting her lip.

Bonnibel acted as if she hadn't heard anything. “Great! Meet me at the underpass by JFK in two hours, and make sure to bring the dog.”

“Yeah, sure,” Marceline grunted, tearing off a piece of her tank top to use as a bandage. She wouldn’t have time to eat and go to the pharmacy, and she wanted a sandwich.

“See you then, sweetheart.” There was a click, and the line disconnected.

Marceline looked at her phone for a moment, but no other calls or texts came through. There were no hints about what to pack, but she could throw together a few weapons and some extra clothes in a few minutes. She reached over and petted Schwabl, smiling as he nuzzled his snout into her hand.

She was still tired and in pain, but she was looking forward to this. Bonnibel always had a few tricks up her sleeve, and Marceline didn’t mind protecting her while she worked. She finished cleaning up her wound, and stood up with a grunt. She had to get moving; it was always better to be early than late.


	2. Shootout

**Summary for the Chapter:**

> Marcy is stuck between several gunmen and a hard place... Luckily, she has Bonnie to help her out.
> 
> Warning: this contains graphic violence and several unnamed characters being murdered.

**Notes for the Chapter:**

> It couldn't be a shoot fic without a nice dump of mutual pining :)
> 
> Thank you to nebula-gaster for beta reading this, I really appreciate it!

Shit, this was not going well. Marceline winced as her gun clicked. The clip was empty.

She ducked behind a wall, gunfire hammering the place she had just been standing. She reached into her pocket, already knowing she would come up empty. That had been the last of her ammunition, and she still had four soldiers after her.

She would’ve thought that the government would give up on her by now, but apparently they still wanted to retire her. It was a shame; these agents could have had promising careers if they hadn’t been sent after her. Marceline had already taken down at least ten, but things were beginning to fall apart. She was getting near the back of the warehouse, and they probably had a sniper trained on the back exit. Her exit vehicle was out front, so she wouldn't be able to get to it without taking out the agents. She had engaged in hand-to-hand combat with someone wielding a gun before, but if the others weren’t distracted somehow then she would just get shot.

She instinctively ducked down as another round of fire went off, this time coming from her left. Shit, they were closing in on her location. The heavy metal shelving units could only hide her for so long. There had to be a way out of this, she just had to think…

There was movement in her peripheral. She whirled around, throwing a punch. She grunted as her assailant caught it, grabbing their other hand before they could hit her back.

Instead of resisting her grip or kicking her, the woman twined their fingers together. Marceline looked at the masked woman with confusion, and she stared back.

Well, if she wasn’t going to act then Marceline would. She used her bodyweight to throw the woman into her cover. The bang echoed out loudly, but it wasn’t loud enough to cover up the familiar groan of pain. Marceline let go of the girl, and grabbed her balaclava. She pulled the hood off, and familiar strawberry blonde locks tumbled out.

“Relax honey, it’s just me.” Bonnie smiled at her, using her foot to drag a duffle bag she’d dropped closer to them.

Marceline glared at Bonnie, tossing the hood into her lap. “What are you doing here?”

“How did you find me?” Marceline flinched as another round of gunfire went off, looking out for any ricochets or stray shards of shrapnel. They might be small, but it was a bitch to pick them all out.

“She told me you might need some help.” Bonnie tapped her earpiece and winked.

Bonnie opened up her bag, revealing two .50 caliber handguns and one M16. She handed the smaller guns over to Marceline, and pressed four spare clips of ammunition into her other hand. She took the M16 for herself, lifting it with a practiced grip. Marceline had the vague feeling that she had seen Bonnie do this before, but she didn’t think Bonnie had used one of these on their missions before. She knew better than to ask about Bonnie’s past, but it was interesting that she knew how to handle so many heavy weapons.

Bonnie leaned in, kissing Marceline’s cheek. She was warm, her lips brushing against the corner of Marceline’s mouth. It was almost like time had slowed down, giving Marceline a chance to savour the touch. She began leaning in, but Bonnie pulled away.

The peck couldn’t have lasted more than a few seconds, but Marceline felt like it had gone on for much longer than that. She licked her lips, staring at Bonnie. They had flirted a few times on missions, but Bonnie had never kissed her like that before.

“Good luck, sweetie.” Bonnie winked, playfully pursing her lips. She paused, her expression going blank as she cocked her head to listen to the Machine. She nodded as she heard the message, her eyes refocusing back on Marceline. “I’ll take the two on the left, you go after the ones on the right.”

Before Marceline had the chance to say anything, Bonnie stood up and fired two shots. Judging by the metal clanging, she had hit someone in the knee and dropped them. She charged forward recklessly, putting her faith in the Machine to protect her.

Marceline scrambled, shoving one of the guns into her holster. She used the other one to cover Bonnie, pinning down the agent closest to them with a few well-placed shots. She desperately wanted to touch her cheek, but she didn’t have time for distractions now. She had to get out of the building, and make sure Bonnie didn’t hurt herself.

Both of the agents were in front of her, but Marceline still glanced back to check her blind spot. No one. She ducked between the shelves, creeping around to the left as quietly as she could.

She peeked around the corner, pausing as she saw the agent. As she crept closer, she recognized the coiling design on his arm. Mulligan, Agent 270819. He’d just come on when she’d been given the boot. He was focused on the scuffling sounds from Bonnie, giving Marceline the perfect chance to creep up behind him.

Bonnie’s musical laugh echoed off the walls, and Marceline snapped. Marceline grabbed the agent’s head and jerked it back, pressing the gun against his back. One clean shot, right in the middle of the spine. The bullet didn’t break the sternum, and she let him go as he slumped to the ground. One more shot to the back of the head, just to be safe.

The last agent seemed to know that they were being hunted, because they got very quiet all of a sudden. Marceline crept between the shelves. This was just like her training exercises; she just had to wait for a slip-up.

A radio crackled, and a gunshot went off. Marceline rushed around the corner, gun up. Bonnie was standing there, the agent’s body at her feet.

“That’s all of them.” Bonnie squatted down, picking up a cellphone. She removed the sim card, and crushed it beneath her heel. Marceline knew better than to ask questions; the answer would always have to do with the Machine. “Let’s go, sweetie.”

Their footsteps echoed in the quiet warehouse, and it put Marceline on-edge. The two of them might be alone, but someone could be watching. The kiss was still on Marceline’s mind, nagging at her like a metal shell embedded in her skin. Did it mean anything, or was this just another one of Bonnie’s games?

Marceline grabbed Bonnie’s shoulder before she could step out of the warehouse, tugging her back. “What was that about?”

She peeked out slowly, her gun in one hand. There were no good sniper vantage points, but that didn’t mean someone couldn’t be hiding out there. She held her gun tightly, not turning the safety on yet. She walked over to the car, double-checking the licence plate number. The Machine had told her 07A3T8 would already be hotwired and ready to use.

“What do you mean?” Bonnie asked, her hand brushing against Marceline’s back as she walked around the car.

“Never mind.” Marceline jerked the driver’s door open, and got inside.

There was no point in trying to understand Bonnie’s behaviour. She would just have to appreciate whatever scraps of affection she got, and not complain. After all, Bonnie had saved her life more than once already. That should be more than enough.


End file.
